Senate Minority Leader Mitch McConnell, who had come under heavy fire last month for his handling of the immigration bill, has performed heroically in recent weeks on several issues, including the war in Iraq, the “Fairness Doctrine” and enemy combatants. In doing so, the Kentucky Republican has been notably successful in advancing conservative principles and illustrating the incompetence and intellectual bankruptcy of the Democratic leadership.

On Wednesday, thanks in large part to Mr. McConnell’s leadership, Senate Democrats came up eight votes short in their effort to obtain cloture on an amendment to begin withdrawing troops from Iraq within 120 days. During debate, Mr. McConnell drove home a point that was clearly embarrassing to Democrats: that even Senate Armed Services Committee Chairman Carl Levin could not explain how his own amendment would work. Sen. Harry Reid, clearly angered by the fact that his latest legislative attempt to undermine the war effort had failed, responded petulantly, pulling the defense authorization bill from the floor. By doing so, the majority leader is holding up funding to assist wounded war veterans, and to provide mine-resistant trucks to protect American soldiers in Iraq and Afghanistan. In short, Mr. McConnell helped expose the fraudulence of Mr. Reid’s argument that the Democratic Party opposes the war but “supports the troops.” In reality, Mr. Reid and his political allies demonstrated that they are more interested in scoring cheap political points against the war than in improving conditions for American fighting men and women.

But Mr. McConnell was only getting warmed up. Late on Thursday, he persuaded the Senate to pass by a 94-3 margin his amendment to an education bill which put the Senate on record in opposition to moving Guantanamo Bay detainees to military bases and jails inside the United States. The vote came as a surprise because many Democrats, among them Sen. Dianne Feinstein of California, view shutting down Gitmo as a great international public-relations move (even if it means that terrorists would be moved into jails located near American cities and towns.) Apparently, the Democrats hadn’t bothered to read the McConnell amendment, so it passed easily.

And last — but certainly not least — Mr. McConnell is doing excellent work in leading the fight against reviving the notorious Fairness Doctrine. With Mr. McConnell’s support, Sen. Norm Coleman has tried to offer as an amendment to other legislation his Broadcaster Freedom Act of 2007. The “fairness” policy was repealed 20 years ago by the Federal Communications Commission. On Thursday, Democrats led by Sen. Ted Kennedy blocked Mr. Coleman from attaching his amendment to the education bill on a 49-48 vote. Thanks in large part to Mr. McConnell’s leadership, however, the overwhelming majority of Republicans have stood firm against any effort to revive the Fairness Doctrine and silence talk radio. That’s effective leadership.